Atypical imaging features of posterior fossa's dermoid cyst: Case report and review of literature

BACKGROUND: Intracranial dermoid cysts are uncommon lesions with characteristic imaging appearances. Symptomatic clinical presentation usually occurs in one of two ways: mass effect or rupture. Radiologically, dermoid cysts typically present as low density masses on computed tomography (CT) scan and are generally hyperintense on T1-weighted magnetic resonance imaging (MRI) sequences with variable signal on T2-weighted sequences. CASE DESCRIPTION: We present the case of a 35-year-old female presented with symptoms of increased intracranial pressure. Radiological investigations showed a cystic posterior fossa tumor that was not only hyperdense on CT scans but also hypointense on MRI T1-weighted images. The patient underwent a total-gross resection of an extra-parenchymal posterior fossa tumor. Pathologic examination of the specimen concluded to dermoid cyst. CONCLUSION: Dermoid cyst of the posterior fossa is a benign lesion surgically treatable. Only an appropriate radiological diagnosis of this lesion would permit a well-targeted therapeutic approach.